Preparation and electrochemical properties of NiMn2O4 spinel oxide cathode

Developing high-performance cathode materials is of great significance to promote the development of intermediate temperature solid oxide fuel cells (IT-SOFCs). In this paper, the spinel-type NiMn2O4 (NMO) electron-ion mixed conductor material was prepared by the sol-gel method, and it was systematically studied as the cathode of IT-SOFCs. It is found that NMO material has stable cubic phase structure by using X-ray diffraction (XRD) and the conductivity of oxygen ions is studied by the technique of electrical conductivity relaxation (ECR). It shows that NMO has excellent oxygen-ion conductivity, which provides guarantee for its electrochemical performance. Impedance spectroscopy measurements of a symmetrical cell shows a low interface impedance, which is only 0.27 Ω•cm-2 at 800℃. At the same time, an anode-supported SOFC with NMO cathode presents a maximum power density of 864.9 mWcm-2 at 800℃. The above results demonstrate that NiMn2O4 is a potential cathode material for IT-SOFCs. © 2020, Chemical Industry Press Co., Ltd. All right reserved.